Voting is underway in Burundi's parliamentary elections despite an opposition boycott and the threat of violence as police battle anti-government protesters in the capital.

Gunfire could be heard in some parts of Bujumbura as voting started at 6 a.m., and there is heavy security across the city.

In the Musaga neighborhood, which has seen violent protests against President Pierre Nkurunziza's bid for a third term, there were few civilians in sight Monday as mostly police and soldiers lined up to vote.

The voting is taking place despite calls by the international community for a postponement until there is a peaceful environment for credible elections.

Bujumbura has suffered unrest since the ruling party announced on April 26 that Nkurunziza would be its candidate in presidential elections scheduled for July 15.